From 308ffa1e814a3956c5de64db20c8e67f61b4eb78 Mon Sep 17 00:00:00 2001
From: Pekka Paalanen <pq@iki.fi>
Date: Mon, 12 May 2008 21:21:02 +0200
Subject: [PATCH] --- yaml --- r: 100611 b: refs/heads/master c:
 2039238b79b51a50f8477f53f33750e1c3fc146a h: refs/heads/master i:   100609:
 c0e59af06d7a351b3d25111b5d78623f1c4bf0af   100607:
 4abbdf989a18db828314010bb95453e1a0777513 v: v3

---
 [refs]                               |  2 +-
 trunk/kernel/trace/trace_mmiotrace.c | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index b376c0f08f33..5337fcbe4642 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d0a7e8ca5b996d36219e6fc002907291c8ee677b
+refs/heads/master: 2039238b79b51a50f8477f53f33750e1c3fc146a
diff --git a/trunk/kernel/trace/trace_mmiotrace.c b/trunk/kernel/trace/trace_mmiotrace.c
index 6d2edbdde939..d0f649a2203d 100644
--- a/trunk/kernel/trace/trace_mmiotrace.c
+++ b/trunk/kernel/trace/trace_mmiotrace.c
@@ -17,11 +17,13 @@ struct header_iter {
 };
 
 static struct trace_array *mmio_trace_array;
+static bool overrun_detected;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
 	int cpu;
 
+	overrun_detected = false;
 	tr->time_start = ftrace_now(tr->cpu);
 
 	for_each_online_cpu(cpu)
@@ -124,12 +126,34 @@ static void mmio_close(struct trace_iterator *iter)
 	iter->private = NULL;
 }
 
+static unsigned long count_overruns(struct trace_iterator *iter)
+{
+	int cpu;
+	unsigned long cnt = 0;
+	for_each_online_cpu(cpu) {
+		cnt += iter->overrun[cpu];
+		iter->overrun[cpu] = 0;
+	}
+	return cnt;
+}
+
 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 				char __user *ubuf, size_t cnt, loff_t *ppos)
 {
 	ssize_t ret;
 	struct header_iter *hiter = iter->private;
 	struct trace_seq *s = &iter->seq;
+	unsigned long n;
+
+	n = count_overruns(iter);
+	if (n) {
+		/* XXX: This is later than where events were lost. */
+		trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
+		if (!overrun_detected)
+			pr_warning("mmiotrace has lost events.\n");
+		overrun_detected = true;
+		goto print_out;
+	}
 
 	if (!hiter)
 		return 0;
@@ -142,6 +166,7 @@ static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 		iter->private = NULL;
 	}
 
+print_out:
 	ret = trace_seq_to_user(s, ubuf, cnt);
 	return (ret == -EBUSY) ? 0 : ret;
 }